The overarching objective of the Morphology Core, under the Directorship of Dr. Katz, is to enhance the ability of the Program Project Leaders and their personnel to perform research utilizing morphologic techniques. The Morphology Core fulfills these through the following interrelated services, all of which have had historical success in advancing the scientific themes of the Program Project: 1) Provide a meticulously organized technical service to the Program Project investigators. The Core processes, embeds, sections, and hematoxylin/eosin stains paraffin and frozen mouse and human tissues. The Core maintains an extensive animal, organotypic (3D) culture and human tissue bank, which is coordinated with the Molecular Biology Core. The Morphology Core is adept in the construction of Tissue Microarrays;2) Support Program Project investigators through instruction of techniques and providing the reagents necessary to perform morphologic analysis of tissues and cells. The Morphology Core will assist Program Project Investigators in the procurement of tissues from animals and humans, provide instruction for in situ hybridization and immunohistochemistry and facilitate use of laser capture microscopy and confocal microscopy. There is extensive microscopy of morphologic experiments. In addition, the Morphology Core has equipment, reference books/atlases, and extensive reagents, all of which are available to the Program Project Investigators;3) Through Dr. Andres Klein-Szanto, an experienced and expert experimental and clinical pathologist, the Core provides: A) Quality assurance and quality control in the integrity of tissue architecture after processing, sectioning and staining;B) Assisting in the design of morphologically related experiments; C) Interpretation of in situ hybridization, immunofluorescence and immunohistochemistry;and 4) Prioritizing the needs of the Projects so services are delivered in a timely, efficient and cost-effective fashion. The Program Project Leaders and their personnel have used the Core extensively and this relationship is certain to be augmented in the future. The utilization of services and facilities within the Morphology Core also provides an ongoing foundation for the promotion of scientific interactions between the Projects. RELEVANCE (See instructions): This Core provides outstanding, unique experience and expertise in the interrogation by the Projects of esophageal and related tissues from organotypic culture and mouse models, as well as human endoscopic and surgical specimens. Imaging analysis is unique as well. The projects prosper as a result of the core services and technologies and this Core advances the mission of the Program Project.